Tracking morphologies at the nanoscale: self-assembly of an amphiphilic designer peptide into a double helix superstructure.

Hierarchical self-assembly is a fundamental principle in nature, which gives rise to astonishing supramolecular architectures that offer an inspiration for the development of innovative materials in nanotechnology. Here we present the unique structure of a cone-shaped amphiphilic designer peptide. When tracking its concentration-dependent morphologies, we observed elongated bilayered single tapes at the beginning of the assembly process, which further developed into novel double-helix-like superstructures at increased concentrations. This architecture is characterized by a tight intertwisting of two individual helices, resulting in a periodic pitch size over their total lengths of several hundred nanometers. Solution X-ray scattering data revealed a marked 2-layered internal organization. All these characteristics remained unaltered for the investigated period of almost three months. In their collective morphology the assemblies are integrated into a network with hydrogel characteristics. Such a peptide based structure holds promise for a building block of next-generation nanostructured biomaterials.